Earlier in the morning, just before voting commenced for the firt phase of the Lok sabha elections, as mnay as four Maoists were arrested at Bedre in Chhattisgarh's Bijapur.

A polling station in Chhatisgarh's Sukma which is a sensitive Red zone. (Photo: News Nation)

A blast was reported from near a polling booth at the Dandwan area of Chhattisgarh's Narayanpur at 4.15 am on Thursday. When the blast occurred, security personnel and polling officers were present at the booth. No damage to life or property has been reported. However, the area has been put on high alert. The blast comes two days after a BJP MLA was killed in a blast in Dantewad.

Narayanpur comes under the Bastar Lok Sabha seat. "The explosion took place around 4.15 am in Farasgaon area on Narayanpur-Dandwan road when a team of security men was escorting polling personnel to their booth," the official said. Naxals had planted the explosive underground and were waiting for the security forces to arrive.

"However, when the rebels realised that security personnel had changed their route and were zeroing-in on them through a forest, they triggered the IED (improvised explosive device) blast in panic and fled the spot," he said. "No harm was caused to the security and polling personnel in the explosion," he added. A thick security blanket, comprising around 80,000 state and paramilitary personnel, was thrown across the Bastar Lok Sabha constituency where polling is being held in its four Assembly segments - Dantewada, Konta, Bijapur and Narayanpur - from 7 am to 3 pm, he said.

Earlier in the morning, just before voting commenced for the firt phase of the Lok sabha elections, as mnay as four Maoists were arrested at Bedre in Chhattisgarh's Bijapur. Three country-made guns were also recovered from them. Polling in Maoist-affected constituencies will conclude at 4 pm, an hour prior to the scheduled deadline of 5 pm in other states.

On Wednesday, a day after a BJP MLA and four policemen were killed in a Naxal attack in Chhattisgarh, an encounter took place between security personnel and the rebels in Rajnandgaon district on Wednesday, a senior police official said.

No casualty was reported from either side in the skirmish, he said.

A joint team of the Special Task Force (STF) and District Reserve Guard (DRG) raided a Maoist camp in Bukmarka hills adjoining Maharashtra state around 1.15 pm, following which a gun-battle broke out between the security forces and Naxals, the official told PTI.

During the exchange of fire, Naxals also triggered three IED (improvised explosive device) blasts, he said.

However, on finding the security personnel zeroing-in on them, the ultras fled towards a forest in Gadchiroli district of Maharashtra, he said.

Some Naxal-related items were recovered from the spot, he said, adding a search operation was underway in the region.

The Rajnandgaon Lok Sabha constituency will go to polls in the second phase on April 18.